Ethereum's Glamsterdam Upgrade Gets a Sepolia Date — but Not a Mainnet One

The Ethereum Foundation on September 17 scheduled Glamsterdam, the network's next upgrade, to activate on the Sepolia test network on October 6, 2026 at 13:53:36 UTC — epoch 353,024, slot 11,296,768 (Ethereum Foundation blog). The same post is explicit that this is a testnet milestone only: activation dates for the Hoodi testnet and for Ethereum mainnet "have not yet been decided" and will be announced separately.

Glamsterdam follows the Fusaka upgrade and pairs the Amsterdam execution-layer changes with the Gloas consensus-layer changes (the name fuses "Gloas" and "Amsterdam," host city of Devconnect 2022). Its two headline features:

• Enshrined proposer-builder separation (EIP-7732), which moves the split between block proposers and builders into the consensus protocol itself. A proposer commits to a builder's payload, the builder later reveals it, and the protocol handles payment — cutting reliance on trusted middleware. It also gives validators more time to validate execution payloads.
• Block-level access lists (EIP-7928), which record the accounts and storage a block touches so clients can read state and validate transactions in parallel.

Alongside those, Glamsterdam reprices gas: EIP-8037 raises and separately meters the cost of creating state, and EIP-8038 updates state-access costs, part of a broader package (EIP-7773 tracks the full list of roughly 17 scheduled EIPs plus supporting networking specs). The Foundation warns that contracts relying on fixed gas stipends, hardcoded gas limits, or assumptions about remaining gas may break, and points developers to a "repricing impact guide."

Key facts

• Sepolia activation: October 6, 2026, 13:53:36 UTC, epoch 353,024 / slot 11,296,768 (Ethereum Foundation).
• Hoodi and mainnet dates: not yet decided (Ethereum Foundation).
• Headline EIPs: 7732 (ePBS), 7928 (block-level access lists), 8037/8038 (gas repricing) (EIP-7773 spec list).
• Client note: Prysm 7.2.0 supports the fork but defaults to a 60M gas limit after activation; validators wanting 200M must set it explicitly, as --suggested-gas-limit has no effect after Gloas (Ethereum Foundation).

The real-world read

The honest framing here is narrower than the excitement Glamsterdam tends to generate. This is a Sepolia announcement — nothing more. There is no mainnet date, no Hoodi date, and the Foundation itself tells mainnet users and ETH holders plainly: "No" action is required. Treat any coverage that reads this as "Ethereum's next upgrade is coming" without that caveat as getting ahead of the facts.

Two practical flags worth heeding. First, the gas repricing is not cosmetic — the Foundation is directly warning that live contracts with hardcoded gas assumptions may need changes, which is a real developer burden, not a footnote. Second, the Prysm gas-limit default (60M unless manually raised to 200M) is the kind of configuration gap that quietly bites validators; the throughput gains ePBS and BALs promise depend on operators actually setting it.

This is news coverage, not financial or technical advice; verify client releases and upgrade steps against official release notes before acting.

Sources

• Ethereum Foundation blog, "Glamsterdam Testnet Announcement" (Sept 17, 2026) — primary source for the activation schedule, EIP list, feature descriptions, and client guidance. Not marketing: it is the protocol organization's own technical announcement, and the only source for this item.